Device for selectively positioning a member in a series of operative positions

ABSTRACT

In a mechanism, suitable for operating the type-carrier of a printing assembly, a device for selectively positioning a member positionable from an inoperative position to a series of operative positions in accordance with a combination code. The code combination corresponding to the operative position to be selected is temporarily stored in a binary pulse-counter which is set to store in binary code the complement of a number representing the number of steps which the member must perform. The member is actuated by resilient means under the control of a cyclically rotating main shaft and is brought back to its inoperative position by the shaft at the end of the cycle.

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code. The code combination corresponding to the 0 position to be selected is temporarily stored in a bina counter which is set to store in binary code the comp PATENTEU AUG 1 719m SHEET 1 [1F 5 INVENTORS FRANCES o sg an g crmu BY j/M M A'i'TORNEY PATENTEUAUBHIHTI 3,599,773

SHEET 3 OF 5 INVENTORS FRANCESCO SERRACCHIOLI NICOLO' GI LITTI BY TTORNEY F H $088 r1 fim m 3 :23 m MW 3 SE28 MEZBU N m \(g munEIw PATENTED AUG 1 719m SHEET UF 5 INVENTORS FRANCESCO SERRACCHIOLI NICOLO' GI urn A in NE! ATENTEU AUG] 7 I97! SHEEI 5 UF 5 I INVENTORS FRANCESCO SERRACCHIOLI NICOLO GIO lTTi BY JLW.

ATTORNEY CROSS-REFERENCE TO RELATED APPLICATION The convention priority application for this invention is Italian application No. l396-A/68 filed on Apr. 23, 1968 in Italy. I

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to mechanisms for positioning multiple character type members and in particular for positioning type members in the form of rotatable wheels.

2. Description of the Prior Art In printing devices in which a type-carrying member rotates continuously and a hammer effect the printing on the passage .of the character selected, it is known to actuate the hammer by means of a control device comprising a counter for pulses generated by a series of elements movable rigidly with the type-carrying member. Such control devices, however, are unsuitable for positioning a member from an inoperative position to a variable operative position.

In another known printing device, the types are carried by a type wheel adapted to be rotated in an invariant direction and the code combination corresponding to the type or character to be selected is stored in a binary counter. The type wheel is rotated andsends a pulse to the counter for each step. When the counter reaches the full state, the wheel is temporarily arrested and printing is commanded. Thereafter, the wheel begins to rotate again to return to rest or the inoperative position, while additional means provide for disconnecting the counter from the pulse generator. These means therefore render the device relatively complicated. Moreover, this device is unsuitable for positioning members movable with a reciprocating motion under the control of a rotating shaft.

The object of the presentinvention is to provide a positioning device which obviates such drawback and is suitable for controlling the selection of the character in a printing mechanism, for example for a data terminal apparatus.

SUMMARY OF THE INVENTION According to the present invention there is provided a devicefor selectively positioning a movable member from an inoperative position in a selected one of a series of operative positions determined by a code combination, comprising a binary counter arranged to store the complement with respect to a number N of a number determined by the code combination and which represents the number of steps of movement required for the member to reach the selected operative position, a cyclically rotating main shaft arranged to move the member from the inoperative position via a resilient coupling arrangement and subsequently to restore the member to the inoperative position, a series of signal-generating elements disposed on the shaft at angular positions corresponding to the said operative positions and arranged as they pass a predetermined position to supply pulses to the binary counter to count this up to N, and a mechanism responsive to the number N being attained to arrest the movable member in the selected operative position for an interval of time preceding the restoration or the member to the inoperative position.

The invention thus solves the technical problem of providing a positioning device for a member movable with a reciprocating motion which permits the member to stop temporarily in the selected position while a main shaft continues to rotate. The device can have the utmost simplicity and reliability of operation.

The invention will be described in more detail, by way ofexample, with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1 to 3 are front perspective views from the left of the printing mechanism of a data terminal apparatus incorporating a positioning device embodying the invention;

FIG. 4 is a front perspective view from the left of a detail of the printing mechanism in a working position;

FIG. 5 is a block diagram of the positioning device embodying the invention; and

FIGS. 6 to 8 are side views of the positioning device from the left.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The positioning device is incorporated in a printing mechanism of a terminal apparatus comprising an alphanumeric accounting machine connected in line with a central computer. The printing mechanism comprises four type wheels 1 (FIG. 1) each of which is provided with 12 characters. Each wheel 1 is pivoted on a corresponding slider 2 slidable on two spindles 3 'fixed to a vertical plate 4 fixed in turn to the middle part of a carriage 6. The four sliders 2 are normally urged forward against the bottom spindle 3 by springs 7. Each type wheel 1 is fast with a pinion 8 meshing with a toothed sector 9 pivoted on the corresponding slider 2 and connected to a tie rod 11 (FIG. 2) slidable vertically in a fork 12 of a connecting rod 13. Each tie rod 11 (FIG. I) is normally urged by a spring 14 against a stop tooth 16 (FIG. 2) of the fork I2. Each tie rod 11 has a notch or slot 17 adapted to engage selectively a bar 18 fixed to a bail l9 turning on a shaft 21. Each connecting rod 13 is normally urged by a spring 22 against a fixed stop 23 and holds the corresponding tie rod ll normally disengaged from the bar 18. Due to the action of a yieldable coupling formed of spring 24, the bail I9 is normally caused to bear against a lug 26 ofa lever 27 fixed on the shaft 21. A twoarmed lever 29 is moreover fixed on the shaft 21 and cooperates with a double cam 31 with complementary profiles which is fixed toa shaft 32 constituting the usual main shaft of the machine. The shaft 32 (FIG. 3) can be actuated cyclically for a revolution in an anticlockwise direction by means of an electric motor (not shown) of the machine, via a clutch 34 (FIG. 2).

The carriage 6 (FIG. 1) is adapted to slide by means of two pins 36 in thefixed frame of the machine parallel to the usual platen 38, which is movable transversely in the machine. The carriage 6 (FIG. 3), when at rest, is centered with respect to the writing point and is provided with two projections 39 and 41 adapted to be arrested against fixed lugs 42 and 43 respectively, to bring the right-hand outside wheel 1 and the lefthand outside wheel 1, respectively, to the writing point. The carriage 6 is moreover provided with two lugs 44 and 46 adapted to cooperate with projections 47 and 48 respectively, of a lever 49 to bring the right-hand inside wheel I and the left-hand inside wheel 1, respectively, to the writing point.

The lever 49 can turn on a fixed spindle S0 and, by the ac- 1 tionof a spring 51, is normally caused to bear on two projecconnected on one side to a tie rod 58 and on the other side to a.

tie rod 59. Due to the action of springs 61 and 62 respectively, the two tie rods 58 and 59 are normally engaged by means of notches 63 and 64 respectively,with a bar 66 fixed to a bail 67 which can turn on the shaft 21.

The bail 67 is normally caused to bearby the action of a spring 68 on an arm 69 fixed to the shaft 21. To the tie rod 58 there is fixed a pin 71 which can cooperate with a projection 72 of each of the two connecting rods 13 which correspond to the two type wheels 1 on the left, while to the tie rod 59 there is fixed a pin 73 which is able to cooperate with a projection 74 of each of the'two connecting rods 13 which correspond to the two type wheels 1 on the right.

Each connecting rod 13 (FIG. 2) is pivoted to a crank 91 fixed on a shaft 92 individual to the rod and turning in the fixed frame of the machine. To each shaft 92 there is fixed a selection tab 93 which can be turned clockwise by a tooth 94 of a slider in a series of sliders 96 each associated with a symbol on the wheels 1. The sliders 96 are of four types which differ from one another by the position of the tooth 94, this determining which connecting rod 13 is shifted and hence effecting selection of the correct print wheel.

Each slider 96 is slidable on two fixed spindles 97 and 98 and is normally held bearing against the shaft 98 by means of a spring 99. On each slider 96 there is pivoted a catch 101 which, by means of a recess 102, normally holds engaged a push member 103 also pivoted on the slider 96 and connected to the catch 101 by means of a spring 104. Each catch'10l is adapted to cooperate with a lug 106 of a shank 107 to which there is fixed a corresponding writing key 108. Each shank 107 is slidable by means of a slot 111 on a fixed spindle 112 against which it is normally urged by a spring 113.

Each catch 101 is adapted to cooperate with a universal bar 114 fixed by means of two arms 116 and 117 to a shaft 118 which can turn in the fixed frame of the keyboard. To the shaft 118 there is fixed a crank 119 connected by means of a connecting rod 121 to a bail 122 which can turn on a shaft 123 rotatable in turn in the frame of the machine. The bail 122 normally holds the clutch 34 open or disengaged by means of a lug 124. Moreover, by means of another arm 126 and under the action of a spring 127, the bail 122 is normally caused to bear against a cam 128 fixed to the shaft 32.

Each push member 103 is adapted to cooperate by means of a shoulder 129 with a universal setting tab 131 fixed to a shaft 132 turning in the fixed frame of the machine. To the shaft 132 there is moreover fixed a crank 133 connected through the medium of a connecting rod 134 to a lever 136 turning on a fixed spindle 137 and normally bearing through the action of a spring 138 against a cam 139 fixed to the shaft 32.

The push members 103 are moreover adapted to cooperate by means ofa tooth 141 (FIG. 4) with a universal resetting bar 142 fixed to a frame 143 which can turn on a fixed shaft 144. The frame 143 is connected in turn by means of a connecting rod 146 to a crank 147 fixed to the shaft 21. The universal resetting bar 142 is also adapted to cooperate with a projection 148 ofeach of the sliders 96.

Each slider 96 (FIG. 2) is provided with a projection 149 which can be brought into the path of a selection tooth 151 fixed to a shaft 152 constituting a member positionable variably from an inoperative position to a series of working positions. The various teeth 151 are fixed to the shaft 152 in a varying angular position corresponding to that of the relative character or type carried by the corresponding one of the type wheels 1. On the shaft 152 there is fixed a pinion 154 constantly in engagement with a toothed sector 156 turning on a fixed spindle 157. The sector 156 is connected to the bail 19 by means of a connecting rod 158.

By depressing a writing key 108, the corresponding shank 107 causes the catch 101 to rotate anticlockwise by means of the lug 106 and the catch then pushes the bar 114 downwards. Through the crank 119 and the connecting rod 121, this bar causes the bail 122 to turn anticlockwise, thus releasing the clutch 34 of the main shaft 32, which begins its rotation of one revolution anticlockwise. The catch 101 moreover disengages the push member 103, which due to the action of the spring 104, turns anticlockwise until the shoulder 129 is brought into the path ofthe tab 131. r g

The catch 101 and the push member 103 now retain each other mutually in the position of FIG. 4, so that the key 108 (FIG. 2) can be released immediately. The key then returns to the high position through the action of the spring 113. The bail 122 now bears by means of the push arm 126 on the high part of the profile of the cam 128 and thus holds the bar 114 in the position reached.

At the beginning of the cycle of the shaft 32, the cam 139 causes the lever 136 to turn anticlockwise, as a result of which the connecting rod 134 is shifted forward. The crank 133 then causes the tab 131 to turn clockwise and the tab, acting on the shoulder 129 of the pushmember 103, shifts the set slider 96 forward. The tooth 94 of the slider 96 then causes the corresponding tab 93 to turn clockwise and, by means of the crank 91, the tab 93 shifts the connecting rod 13 forward, engaging the notch 17 of the tie rod 11 with the bar 18 of the bail 19.

Let it be assumed, for example, that the tie rod 11 associated with the right-hand outside wheel 1 corresponds to the key 108 which has been depressed. By means of the projection 74 (FIG. 3), the corresponding connecting rod 13 also causes the tie rod 59 to turn anticlockwise and terminate its engagement with the bar 66. At the same time, the cam 31 causes the lever 29 to turn clockwise together with the shaft 21. The crank 147 (FIG. 4) thus rotates clockwise and causes the frame 143 to turn clockwise by means of the connecting rod 146. The universal resetting bar 142 thus moved upwardly and, encountering the push member 103, causes this to be reengaged by the catch 101 in the inoperative position of FIG. 2. Moreover, the bar 142 (FIG. 4) is arranged behind the projection 148 of the slider 96, preventing the latter moving to the rear when it is released by the tab 131 until towards the end of the cycle.

At the same time, the lever 27 (FIG. 2) carries the bail l9 clockwise by means of the spring 24 and the bail causes the toothed sector 156 to turn anticlockwise by means of the connecting rod 158. The pinion 154 and the shaft 152 then rotate clockwise together with the teeth 151, while the bar 18 carries the selected tie rod 11 downwardly, causing the corresponding sector 9 (FIG. 1) to rotate. This sector, in turn, also causes the selected type wheel 1 (FIG. 1) to rotate until the tooth 151 (FIG. 2) corresponding to the key 108 depressed is arrested against the projection 149 of the respective slider 96. The type wheel 1 (FIG. 1) thus remains positioned with the selected type or character facing the platen 38. The arm 69 (FIG. 3), in turn, also causes the bail 67 to turn clockwise by means of the spring 68. The bar 66 then causes the tie rod 58 to move downwardly and rotate the rocking lever 56 anticlockwise. The carriage 6 is then shifted to the left to be stopped by the projection 39 against the fixed lug 42. In this position, the right-hand outside type wheel 1 is at the writing point and the respective slider 2 is in correspondence with a hammer 77 (FIG. 1).

If the connecting rod 13 corresponding to the right-hand inside type wheel 1 is shifted forward, the projection 53 (FIG. 3) of the corresponding connecting rod 13 causes the lever 49 to turn anticlockwise. In this case, the lateral movement of the carriage 6 is arrested when the lug 46 encounters the righthand projection 48 of the lever 49, as a result of which the right-hand inside type wheel 1 is brought into the writing position. Similar operations take place when the connecting rods 13 corresponding to the left-hand outside and inside type wheels 1 are set. In this case, the tie rod 58 remains at rest or inoperative and the tie rod 59 is shifted downwardly and causes the carriage 6 to move to the right.

The slider 2 which has been brought to the writing point has a shoulder 76 in the path of the hammer 77 which is fixed to a spindle 78 turning in the fixed frame of the machine and is centered at the writing point. To this end, on the spindle 78 there is fixed an arm 79 having a circular profile normally bearing on a roller 82 rotatable on the lever 27. Moreover, the hammer 77 is adapted to cooperate by means of a tongue 83 with a catch 84 which can turn on a fixed shaft 86 and is normally caused to bear against the tongue 83 by the action of a spring 87. The catch 84 is adapted to cooperate by means of another arm 88 with a lug 89 of the lever 27 In each case, when the selected character is located at the writing point, the lever 27 (FIG. 2) completes its clockwise rotation, stretching the spring 24. The roller 82 (FIG. 1) of the lever 27 now slides on the circular profile 80 of the arm 79 until it leaves the same. The arm 79 then rotates slightly anticlockwise through the action of the spring 81 and urges the hammer 77 along as it rotates until the tongue 83 is stopped on the catch 84. Continuing its rotation, the lever 27 strikes by means of the lug 89 against the arm 88 of the catch 84,which is then compelled to rotate and release the tongue 83 of the hammer 77. Under the action of the spring 81, the hammer rotates anticlockwise and operates the writing slider 2 (FIG. 1) of the selected wheel 1, which therefore strikes against the platen 38.

Towards the end of the cycle of the shaft 32, the lever 27 is rotated anticlockwise and the roller 82 causes the hammer 77 to be reengaged by the catch 84. At the same time, the resetting bar 142 (FIG. 4) of the frame 143 is brought back to the inoperative state followed by the selected slider 96, which is thus brought back into the inoperative position by the spring 99.

At the end of the cycle of the shaft 32 (FIG. 2), the cam 128 permits the arm 126 to jump clockwise due to the action of the I spring 127, so that the lug 124 reopens or disengages the clutch 34.

The various alphanumeric characters of the four wheels 1 can also be written under the control of code combinations in the form of electric signals received from a central data processing system, so that the printing mechanism is used as a data terminal. This is controlled by an electronic control unit 160 (FIG. 5), for example of the type described in 11.5. Pat. application Ser. No. 764,708, filed Oct. 3, 1968, and assigned to the present assignee. The electronic control unit 160 is adapted to receive from a central processing unit on a channel 161 the data coded in accordance with any knowncode. The unit 160 transmits the data via a channel 162 to a transcoding unit 163. The output of the latter is constituted by six lines A, B, C, D, E, F each provided for one bit of the transcoded sixbit code.

The code of the combinations of signals on the lines A-F is chosen in such manner that all the characters having the same angular position on the four wheels 1 are associated with the same combination of the four signals on the lines A, B, C, D. The code of these four signals is of the binary type of weights 1, 2, 4, 8, so that it is adapted to supply l6 difierent combinations. Moreover, the signal on the line A signifies characters which are situated on the wheels 1 in an angular position corresponding to an odd number of angular steps while the absence of this signal signifies characters in an even position. On the other hand, the alphanumeric characters of each wheel 1 are associated with a corresponding combination of the two signals on the lines E, F, which give four different combinations.

The lines E, F are connected to the input of a register 165 with two binary places and having four lines 166 at its output. Each line 166 is adapted to keep an electromagnet 168 associated with one of the wheels I normally energized. The register 165 is adapted to deenergize a single one of the electromagnets 168 for each combination of the two code signals stored on the lines E, F. The lines A, B, C, D are connected to an input of an electronic comparison device comprising a signal inverter I69 and a pulse counter 170 having four binary places. The counter 170 is adapted to emit a signal on recep tion of a pulse corresponding to the position to be selected for the shaft 152 (FIG. 7,) as will be seen hereinafter. More particularly, this signal is adapted to drive a stop electromagnet 174 (FIG. 5) via a bistable flip-flop 171. This is normally in an active state to keep the electromagnet energized.

On the shaft 32 (FIG. 6) there is fixed a disc 172 provided at its periphery with a series of plates 173 of ferromagnetic material and each disposed in the angular position which the shaft 32 assumes when a wheel 1 brings each of its characters into the writing position, taking account of the motion which the cam 31 (FIG. 2) and the members 27, 19, 11 and 12 impart to the wheels 1 until the shaft 152 is arrested. Outside the disc 172 (FIG. 5) there is disposed a signal generator constituted by a magnetic detector 178, the primary of which is fed by a source 175 of direct current to create a magnetic field on core 176. A signal is induced in the secondary of the detector 178 every time one of the plates 173 passes into correspondence with the core 176. The line of the secondary is con nected to a shaping circuit 17 7 (FIG. 5) adapted to transform the signals into electric pulses of square form of the same sign and to amplify them to send them to the binary counter 170.

The line A is moreover adapted to drive an odd-and-even electromagnet 185 via a bistable flip-flop 186 which normally keeps the electromagnet 185 energized. The flip-flop 186 is changed over by the signal on the line A to deenergize the electromagnet 185 every time a code combination represents a character in an odd angular position on a wheel 1.

The circuit 177 is moreover connected to a counter 182 adapted to generate a signal on a line 183 immediately after the circuit 177 has sent the last of the 12 pulses generated in a cycle of the shaft 32 by the detector 178, in correspondence with the 12 character positions of each wheel. The line 183 is directly connected to the control unit 160 for passing a code combination to the input of the transcoder 163 from time to time by means of the signal generated by the counter 182. The line 183 is moreover connected to another input of the flipflops 171 and 186, of the register 165, and of the counter 170 to bring the apparatus back to the initial state at the end of the cycle of the shaft 32. I

A circuit 187 is provided for starting the printing terminal, this circuit being adapted to emit a start signal indicating that the printing mechanism is ready to receive. The circuit 187 is connected to a flip-flop 189 adapted to drive a start elec tromagnet 192, which is normally deenergized. The flip-flop 189 can be changed over to energize the electromagnet 192 when the circuit 187 emits said start signal.

The flip-flop 189 is adapted to be brought back into the inactive position to deenergize the start electromagnet 192 whenever a decoder 188 recognizes the presence of the lines A-F of a particular stop code combination normally transmitted by the control unit via the transcoder 163 at the end of each block of data transmitted.

Each electromagnet 168 (FIG. 6) normally holds an armature 199 attached in opposition to the action of a corresponding spring 198. The armature 199 can turn on a fixed shaft 202 and is connected by means of a pin 203 to a transfer element on slider 204. Each slider 204 is slidable by means of a slot 206 on a pin 205 on each connecting rod 13. Each slider 204 is provided with a tooth 208 adapted to cooperate with the universal setting tab 131. Normally, the four teeth 208 are out of the path of the tab 131. The connecting rods 13 provided with a tooth 209 adapted to be engaged by a lug 207 of a lever 211 pivoted on the shaft 144 and normally bearing against the universal bar 142 through the action ofa spring 210.

The odd-and-even electromagnet (FIG. 7) normally holds an armature 213 similar to the armatures 199 attracted in opposition to the action ofa spring 212. The armature 213 is connected by a pin and slot to a lever 214 pivoting on a fixed spindle 216. The lever 214 is connected by means ofa spring 217 to a lever 218 also pivoting on the spindle 216 and normally bearing against a lug 219 of the lever 214.

The lever 218 is adapted to cooperate by means ofa lug 221 with the rear ends 222, 223 of two pawls 224, 226, respectively, pivoted on a fixed shaft 227. Normally, the lug 221 is located in correspondence with the end 223 of the pawl 226 and with a gap 228 of the pawl 224. By the action of a spring 227', each pawl 224, 226 normally bears against a lug 229 ofa lever 230 to which the armature 231 ofthe stop electromagnet 174 is fixed.

The pawl 224 is adapted to come into engagement with the teeth of a wheel 232, while the pawl 226 is adapted to come into engagement with the teeth of a second wheel 233 similar to the wheel 232. The two wheels 232 and 233 are fixed on the shaft 152 and their teeth are pitched at double the distance corresponding to one step of movement of the shaft 152. The teeth of each wheel are offset from those of the other wheel by the distance corresponding to one step of movement. The

various angular positions of the shaft 152 in which the wheel 232 can come into engagement with the pawl 224 are related to the different possible rotations of the type wheel 1 by an even number of angular steps starting from their inoperative position. Similarly, the various angular positions of the shaft 152 in which the wheel 233 can come into engagement with the pawl 226 are related to the different possible rotations of the type wheels 1 by an odd number of angular steps from their inoperative position.

The start electromagnet 192 (FIG. 6) comprises a cylindrical plunger 233' slidable in an energizing coil 234 and connected by a pin and slot to a lever 236 which can turn on a fixed spindle 237. The lever 236 is provided with a pin 238 which, due to the action of a spring 239, holds a lever 241 so that it is normally turned clockwise in opposition to the action of a spring 242 stretched between the lever 236 and the lever 241.

The lever 241 is adapted to cooperate by means of a lug 246 with a stop tooth 247 of a slider 248 connected in turn to a crank 249 (FIG. 8). The crank is fast with a locking tab 251 adapted to cooperate with the shank 107 of each writing key 108 of the machine. The crank 249 is normally held by the action of a spring 252 against a fixed stop 253, as a result of which the tab 251 is out of the path of the various shanks 107 and the keyboard is thus unlocked.

Moreover, by means of a lug 252', the lever 236 (FIG. 6) normally holds engaged a three-armed lever 253' turning on the shaft 123. The lever 253 is equipped with a roller 256 adapted to cooperate with a cam 257 on the shaft 32. The lever 253 is connected to a slider 258 slidable on the shaft 227 (FIG. 7) and adapted to cooperate by means of a tooth 261 (FIG. 6) with a pin 262 fixed to the bail 122 for releasing the clutch 34. The slider 258 (FIG. 6) is normally retained by the lever 253 in the position shown in the drawing in opposi tion to the action of a spring 255 and is connected by a pin and slot to a bail 264 turning on a fixed shaft 266. The ball 264 is provided with a crosspiece 267 normally urged by the slider 258 against the armatures 199 and 213, (FIGS. 6 and 7) of the four electromagnets 168 and the electromagnet 185. The slider 258 (FIG. 7) moreover normally urges the lever 230 clockwise by means of a projection 268 in opposition to a spring 269.

Finally, by means of a projection 274 (FIG. 8), the slider 258 holds a lever 277 turning on a fixed shaft 278 in such manner that the lever is turned anticlockwise in opposition to the action of a spring 276. The lever 277 is adapted to cooperate by means of a shoulder 279 with a pin 281 of the crank 249 and is adapted to cooperate by means of a projection 282 with a lug 283 of the crank 119, which is normally situated in the position of FIG. 8. The lug 283 (FIG. 2) is provided with an extension 284 adapted to cooperate with a notch 286 (FIG. 8) in the crank 249.

The lever 277 is moreover provided with a lug 287 normally situated in front of a projection 288 ofa slider 289 slidable on a fixed pin 291. The slider 289 is normally caused to bear by the action ofa spring 292 against a lug 293 ofa lever 294. This lever can turn on a fixed spindle 296 and, due to the action of a spring 290, normally bears against a pin 295 fixed to the connecting rod 146 operating the resetting bar 142 (FIG. 4). The slider 289 (FIG. 8) is moreover held by the spring 292 so that it bears against a pin 289 fixed to the crank 133 fast with the universal setting bar on the tab 131 (FIG. 2).

Finally, the slider 289 (FIG. 8) is adapted to cooperate by means of a lug 299 with a shoulder 301 of a lever 302 which can turn on the spindle 227 and normally bearing by the action ofa spring 303 against a stop pin 304. Against a lug 306 of the lever 302 there normally bears a pawl 307 biased by a spring 308 stretched between the bail 302 and the pawl 307. The pawl can turn on the spindle 227 and is adapted to come into engagement with a toothed wheel 309 fixed to the shaft 152. The wheel 309 is provided with the number of teeth equal to the number of characters on the type wheels 1.

The operation of the printing mechanism on reception of code combinations takes place in the following manner.

When the start signal is issued by the circuit 187 (FIG. the flip-flop 189 is activated to energize the start electromagnet 192. The plunger 233' (FIG. 6) is then attracted and causes the lever 236 to turn clockwise and release the lever 241, from the pin 238 and disengage the lug 252' from the lever 253 thus releasing the slider 258. The lever 241, urged by the spring 242, then turns anticlockwise until it bears against the tooth 247 of the slider 248. In turn, the slider 258, due to the action of the spring 255, is shifted forward (to the right in the drawing), causing the lever 253' to turn anticlockwise until the roller 256 bears against the profile of the cam 257. The slider 258 moreover disengages the lever 230 (FIG. 7) from the projection 268 of slider 258 and, by causing the bail 264 to turn clockwise, disengages the armatures 199 (FIG. 6) of the four electromagnets 168 and the armature 213 (FIG. 7) of the electromagnet 185. By shifting forward, the slider 258 (FIG. 8) also disengages the projection 274 from the lever 277 which, due to the action of the spring 276, then turns clockwise until it bears by means of the projection 282 on the lug 283 of the crank 119. After a certain travel, the slider 258 (FIG. 6) engages the pin 262 by means of the tooth 261 and causes the bail 122 to turn anticlockwise, thus releasing the writing clutch 34, so that the main shaft 32 begins to rotate anticlockwise.

Moreover, via the tie rod 121 (FIG. 8) and the crank 119, the bail 122 causes the lug 284 to be lowered, bringing it into correspondence with the notch 286 in the crank 249. The lever 277 released in this way turns clockwise due to the action of the spring 276, and, acting in the pin 281, causes the crank 249 to turn in the same sense, the spring 276 prevailing over the spring 252 and the slider 248 being shifted forward. The universal tab 251 thus turns together with the crank 249, being brought below the shanks 107 of the keys 108 and locking the keyboard for the entire duration of the message to be written. At the same time, the crank 249 engages the lug 284 to the crank 119 by means of the notch 286, thus ensuring the release of the clutch 34 (FIG. 6), as a result of which the shaft 32 can rotate continuously. The lever 241, now no longer prevented by the tooth 247, turns anticlockwise due to the action of the spring 242 and locks the slider 248 in the forward position.

During the first cycle of the shaft 32, the selection operations of the machine are not effected, since the electromagnets 168, 185 and 174 (FIG. 5) are energized. The hammer 77 is therefore actuated idly against the fixed plate 4 (FIG. 1). More particularly, the slider 258 (FIG. 6) is restored by the cam 257 together with the bail 264 and the lever 230 (FIG. 7), while the slider 289 (FIG. 8) is actuated as will be described better hereinafter for the following cycle of the shaft 32 (FIG. 5). The 12 signals detected by the detector 176 now arrive in succession at the counter 170.

When the circuit 177 receives the last of these signals, the circuit 182, by means of the line 183, returns to the inoperative state the flip-flops 171 and 186, the register and the counter 170, while it sends to the control unit 160 a signal which supplies to the lines AF the first code combination to be written. The signals of this combination on the lines E, F are then stored in the register 16:, which causes only one of the electromagnet's 168 (FIG. 6) to be deenergizc selectively. The signals on the lines A, B, C, D, on the other hand, arrive inverted by the circuit 169 and are stored in the counter 170, which thus contains the complement to l6 of the number representing the position to be selected. Moreover, assuming that the character selected is in an even position on the relative wheel 1, the line A carries no signal and the electromag' net remains energized. The armatures of the electromagnets 168 and 185, however, are temporarily retained by the bail 264 (FIG. 6), since the roller 256 of the lever 253 is located on the high part of the cam 257.

At the end of the first cycle of the shaft 32, the roller 256 jumps on to the lowest part of the cam 257 due to the action of the spring 255, as a result of which the slider 258 shifts forward again and brings the bail 264 and the lever 230 (FIG. 7) back into the beginning-of-cycle position described hereinbefore. The armature of the deenergized electromagnet 168 (FIG. 6) is then turned clockwise by the spring 198, so that the slider 2041 is lowered and brings its tooth 208 in front of the universal tab 131.

When the tab 131 is now turned clockwise, by acting on the tooth 208 of the selected slider 204, it shifts forward the corresponding connecting rod 13, on the one hand, thus selecting (as already described) the type wheel 1 on which the character to be printed is located, while on the other hand the crank I33 withdraws the pin 298 (FIG. 8) from the slider 289. Also, the frame 143 (FIG. 6) releases the lever 211 by means of the universal bar 142 and the lever then turns clockwise and engages the tooth 209 of the selected connecting rod 13 by means of the lug 207.

In turn, when the connecting rod 146 (FIG. 8) is shifted to the rear, it permits the spring 290 to rotate the lever 294 anticlockwise, thus releasing the slider 289 from the lug 293. Due to the action of the spring 292, the slider 289 is then rotated clockwise and shifted forward until it engages the shoulder 301 of the lever 302. Meanwhile, due to the action of the cam 31 (FIG. 2) via the bail 19 the connecting rod 158 of the toothed sector 156, the shaft 152 turns clockwise.

Correspondingly, the detector 178 (FIG. 6) detects in succession the passage of the ferromagnetic plates 173 and for each of'these it generates a signal which, via the circuit 177 (FIG. 5), fills the binary counter 170. As soon as this receives the pulse corresponding to the preselected position, that is as soon as the type wheel 1 has completed a number of steps equal to the complement to 16 of the number stored in the counter I70, this will have stored the number l6 formed in binary code by lllllll and emits a signal which changes over the flip-flop 171, thus deenergizing the electromagnet 174. Due to the action of the spring 269, the lever 230 (FIG. 7) then turns anticlockwise, releasing the pawls 224 and 226 from the lug 229 and the pawls rotate in the same sense due to the action of the respective springs 227.

If, as assumed, the electromagnet 185 is not deenergized, the pawl 226 is arrested by the lug 221, while the pawl 224 is engaged in the gap in the wheel 232 which is in its path at that instant. The pawl 224 therefore stops the following tooth of the wheel 2352 together with the shaft 152 in the position corresponding to the character to be written and disposed in an even position on the corresponding wheel 1.

If, on the other hand, the character is to be written is in an odd position, a signal is present on the line A (FIG. 5), as a result of which the flip flp 186 is rendered inoperative and deenergizes the electromagnet 185. The lug 221 is then in the path of the shoulder 222, so that the pawl 224 is arrested by the lug 221, while the pawl 226 can turn until it comes into engagement with the wheel 233, thus arresting the shaft 152 in the position corresponding to the odd character to be written, immediately after the stopping of the shaft 152 and before the hammer 7'7 (FIG. ll) effects the printing.

As soon as the counter 182 (FIG. counts the last of the 12 signals emitted by the detector 176, the following code combination to be written is passed to the lines AF from the control unit I60 and at the same time the components 165, E70 173 and 586 are brought back to the inoperative state.

The universal bar 331i (FIG. 2) turns anticlockwise, returning to the inoperative position, and causes the slider 289 to shift to the rear by means of the pin 298 (FIG. 8), thus causing the lever 302 to turn anticlockwise. The lug 306 now permits the pawl 307 to come into engagement with the wheel 309, thus securing the position reached by the shaft 152. At the same time, the cam 257 causes the slider 258 to shift to the rear and bring back to rest through the bail 264 the armature I99 (FIG. 6) ofthe deenergized electromagnet 168 and armature 2.13 (FIG. '7) of the electromagnet I85, and through the lever 230 the armature of the electromagnet 174. Almost simultaneously there takes place the printing of the character preselected as hereinbefore described, its position in front of the writing point being now determined by the engagement of the pawl 307 (FIG. 3) with the wheel 309. Towards the end of the cycle of the shaft 32 (FIG. 6) the frame 143 returns to its rest position, as a result of which the lever 21 1 releases the engaged connecting rod 13. In turn, the connecting rod 146 (FIG. 8) returns forward and pushes the lever 294 by means of the pin 295 until the lug 293 causes the slider 289 to turn anticlockwise and release the lever 302. The spring 303 then turns the lever 302 clockwise and disengages the pawl 307 from the wheel 309, so that the shaft 152 can be brought back to the inoperative position. The writing cycles follow one another uninterruptedly as long as the control unit transmits the characters to be written, since the lever 236 (FIG. 6) does not reengage the lever 253 at the end of each cycle.

When the stop code combination is received on the lines AF, it is recognized by the decoder 188 (FIG. 5) and the flip-flop 189 is rendered inoperative, so that the start electromagnet 192 (FIG. 6) is deenergized. Due to the action of the spring 239, the lever 236 then turns slightly anticlockwise until it is brought by means of its lug 252' against the lever 253'. Then, as soon as the cam 257 causes the lever 253 to turn clockwise, the lug 252 is engaged by the lever 253 in the position showing the drawing. Moreover, the lever 236 causes the lever 24] to turn clockwise by means of the pin 238, thus releasing the tooth 247 of the slider 248. Moreover, when the slider 258 (FIG. 8), moving to the rear as described before, brings the lever 277 back into its initial position by means of the projection 274, then the crank 249, biased by the spring 252, turns anticlockwise, thus unlocking the keyboard and also releasing the lug 284 of the crank 119. At the end of the cycle of the shaft 32, the bail 122 (FIG. 6) now reopens the clutch 34.

We claim:

1. A device for selectively positioning a reciprocable member movable from an inoperative position to a selected one of a plurality of operative positions determined by corresponding code combinations, comprising a cyclically rotating main shaft, intermediate means including a yieldable coupling, said intermediate means being operated by the shaft for moving the member from the inoperative position and for subsequently positively restoring the member to the inoperative position, wherein the improvement comprises:

a first binary counter having a capacity equal to a predetermined number which is not less than the number of said plurality of positions,

means for generating and storing the complement with respect to said predetermined number of a number determined by the code combination, said complement representing the number of steps of movement required for said member to reach the selected operative positions,

a plurality of signal-generating elements disposed on the shaft at angular positions corresponding to the said operative positions and arranged as they pass a predetermined position to supply counting pulses to the binary counter,

a mechanism responsive to the attainment by the first binary counter of said predetermined number to arrest the member in the selected operative position for an interval of time preceding the restoration of the member to the inoperative position, and

a further counter having a capacity equal to the number of said plurality of positions and connected to count the said pulses and to supply a signal to reset said first binary counter when the last one of said plurality of signalgenerating elements passes the predetermined position.

2. A device according to claim I, further comprising at least one type-carrying member, means for casing the movable member to operate said type-carrying member to select a type for printing in accordance with the code combination, a control unit for sequentially receiving a set of code combinations from a store, and means controlled by the further counter to cause the next code combination to be entered from said store into the first counter in the form ofthe corresponding complemented number.

3. A device according to claim 2, wherein said type-carrying member is part ofa printing mechanism comprising a group of independently movable type-carrying members, and including shifting means for shifting said group of type-carrying members in a first direction to position one of the type-carrying members in a printing position, the type-carrying member in the printing position being operated by the moveable member to be moved in a second direction to select a type for printing, the device further comprising a register, the control unit being connected to said binary counter to furnish a first part of the signals constituting a code combination thereto and being connected to said register to furnish a second part of these signals to said register, said register controlling said shifting means for shifting the type carrying members in the first direction.

45. A device according to claim 3, wherein said intermediate means includes a universal bar and wherein said register is connected to control a series of electromagnets the armatures of which are individually connected to the type-carrying members through respective transfer members, the register selecting one of the electromagnets determined by said second part of the code combination signals to engage the corresponding transfer member with said universal bar which is actuated cyclically by the main shaft to connect the corresponding type-carrying member to the movable member.

5. A device according to any of claim 4, comprising a locking mechanism for locking the armatures of said series of eiectromagnets in position and controlled by the main shaft to unlock the armatures in part of the cycle for release of the armature of that electromagnet which is selected by the register.

it. A device according to claim 4, comprising a further electromagnet with an armature connected to stop means for said movable member wherein said binary counter is connected to control said turther electromagnet, the further eiectromagnet operative when the count in said binary counter reaches said predetermined number to cause the stop means to arrest the movable member, the types on the various type-carrying members corresponding to the same number of steps of movement of the movable member from the inoperative position all having the same combination of signals in the said one part of the signals constituting the code combination.

7. A device according to claim 6, wherein the stop means comprise two series of stops fixed to the movable member, the stops in each series being spaced by double the distance corresponding to one step of movement of the movable member and offset with respect to the stops of the other series by the said distance, and two counter stops associated with the two series respectively and controlled by a mechanism responsive to one signal in the said one part of the signals constituting the code combination to select one counter stop or the other, depending upon whether this one signal is present or absent.

8. A device according to claim 7, wherein the last said mechanism comprises another electromagnet whose energization is controlled by the said one signal and whose armature selects one counter stop or the other, depending upon whether it is attracted or released.

9. A device according to claim 7, wherein the movable member is an oscillating rotary shaft, the two series of stops are constituted by two toothed wheels on said rotary shaft and the two counter-stops are two pawls arranged to be released cyclically responsive to rotation of said main shaft to allow the selected pawl to engage the corresponding toothed wheel.

10. A device according to claim 9, wherein a third toothed wheel is on said rotary shaft and has teeth with half the pitch of the teeth of either of the said two toothed wheels and said main shaft is arranged to engage a further pawl with the third toothed wheel to lock the rotary shaft in the selected operative position during a part of the rotation of said main shaft. 

1. A device for selectively positioning a reciprocable member movable from an inoperative position to a selected one of a plurality of operative positions determined by corresponding code combinations, comprising a cyclically rotating main shaft, intermediate means including a yieldable coupling, said intermediate means being operated by the shaft for moving the member from the inoperative position and for subsequently positively restoring the member to the inoperative position, wherein the improvement comprises: a first binary counter having a capacity equal to a predetermined number which is not less than the number of said plurality of positions, means for generating and storing the complement with respect to said predetermined number of a number determined by the code combination, said complement representing the number of steps of movement required for said member to reach the selected operative positions, a plurality of signal-generating elements disposed on the shaft at angular positions corresponding to the said operative positions and arranged as they pass a predetermined position to supply counting pulses to the binary counter, a mechanism responsive to the attainment by the first binary counter of said predetermined number to arrest the member in the selected operative position for an interval of time preceding the restoration of the member to the inoperative position, and a further counter having a capacity equal to the number of said plurality of positions and connected to count the said pulses and to supply a signal to reset said first binary counter when the last one of said plurality of signal-generating elements passes the predetermined position.
 2. A device according to claim 1, further comprising at least one type-carrying member, means for casing the movable member to operate said type-carrying member to select a type for printing in accordance with the code combination, a control unit for sequentially receiving a set of code combinations from a store, and means controlled by the further counter to cause the next code combination to be entered from said store into the first counter in the form of the corresponding complemented number.
 3. A device according to claim 2, wherein said type-carrying member is part of a printing mechanism comprising a group of independently movable type-carrying members, and including shifting means for shifting said group of type-carrying members in a first direction to position one of the type-carrying membErs in a printing position, the type-carrying member in the printing position being operated by the moveable member to be moved in a second direction to select a type for printing, the device further comprising a register, the control unit being connected to said binary counter to furnish a first part of the signals constituting a code combination thereto and being connected to said register to furnish a second part of these signals to said register, said register controlling said shifting means for shifting the type carrying members in the first direction.
 4. A device according to claim 3, wherein said intermediate means includes a universal bar and wherein said register is connected to control a series of electromagnets the armatures of which are individually connected to the type-carrying members through respective transfer members, the register selecting one of the electromagnets determined by said second part of the code combination signals to engage the corresponding transfer member with said universal bar which is actuated cyclically by the main shaft to connect the corresponding type-carrying member to the movable member.
 5. A device according to any of claim 4, comprising a locking mechanism for locking the armatures of said series of electromagnets in position and controlled by the main shaft to unlock the armatures in part of the cycle for release of the armature of that electromagnet which is selected by the register.
 6. A device according to claim 4, comprising a further electromagnet with an armature connected to stop means for said movable member wherein said binary counter is connected to control said further electromagnet, the further electromagnet operative when the count in said binary counter reaches said predetermined number to cause the stop means to arrest the movable member, the types on the various type-carrying members corresponding to the same number of steps of movement of the movable member from the inoperative position all having the same combination of signals in the said one part of the signals constituting the code combination.
 7. A device according to claim 6, wherein the stop means comprise two series of stops fixed to the movable member, the stops in each series being spaced by double the distance corresponding to one step of movement of the movable member and offset with respect to the stops of the other series by the said distance, and two counter stops associated with the two series respectively and controlled by a mechanism responsive to one signal in the said one part of the signals constituting the code combination to select one counter stop or the other, depending upon whether this one signal is present or absent.
 8. A device according to claim 7, wherein the last said mechanism comprises another electromagnet whose energization is controlled by the said one signal and whose armature selects one counter stop or the other, depending upon whether it is attracted or released.
 9. A device according to claim 7, wherein the movable member is an oscillating rotary shaft, the two series of stops are constituted by two toothed wheels on said rotary shaft and the two counter-stops are two pawls arranged to be released cyclically responsive to rotation of said main shaft to allow the selected pawl to engage the corresponding toothed wheel. l0. A device according to claim 9, wherein a third toothed wheel is on said rotary shaft and has teeth with half the pitch of the teeth of either of the said two toothed wheels and said main shaft is arranged to engage a further pawl with the third toothed wheel to lock the rotary shaft in the selected operative position during a part of the rotation of said main shaft. 